Pneumatic tool



(No Model.)

' J. G. CARLINBT.

PNEUMATIC TOOL.

Patented Sept. 10

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6 4 QNMQNLN Unteren dramas Pernaut @sereno JOHN G. CARLNET, OF PI'HLADELPHIA, PENNSYLVANIA.

PN EUNIATIC TOOL.

SPECIFICATION forming part of Letters Patent No. 546,223, dated September 10, 1 895. hpplicationiled May 27, 1895. Serial No. 550,812. ille model.)

To t2/'Z whom t may concern.:

Be it known that I, JOHN G. CARLINET, a citizen of the United States, residing in Philadelphia, Pennsylvania, have invented certain Improvements in Pneumatic Tools, of which the following is a specification.

The object of my invention is to. seconstruct a pneumatic tool that it can be made of few parts, andin which asingle valve controls the admission of iiuid under pressure to the ends of the cylinder.

A further object is to so arrange the toolcarrier in the casing that it will not be affected by the tluid in the cylinder when the hammer is returned.

A still further object is to so construct the parts that the vibration of the tool will autou matically cease as soon as removed from the Work, dispensing entirely with the ordinary hand-valves.

These objects I attain in the following manner, reference being had to the accompanying drawings, in Which- Figure l is a longitudinal sectional View of my improved pneumatic tool.' Fig. 2 is a transverse sectional view on the line 2 2, Fig. 1. Fig. 3 is a transverse sectional View on the line 3 3, Fig. l. Fig. 4 is a longitudinal sectional view of the tool in its simplest form. Fig. 5 is a transverse sectional view on the line 5, Fig. 4.

A is the casing of the tool, preferably made in the form illustrated', and screwed into the casing is a cap A having an extension A2 to which the iiexible fluid-pipe is connected. The casing A has at the opposite end an eX- tension A3, in which the tool-carrier C finds its bearin g. The head o of the tool-carrier Works between a shoulder1 on the 'extension As and the follower a, which is screwed into the eX- tension A3.

B is the plungenhammer having a portion i), which at all times rests in the channel d in the casing. This projection of the hammer strikes the head c of the tool-carrier at each reciprocation of the hammer, and in the extension A3 is a venta2 communicating with 'the channel a at all times, so that the pressure of the luid will lnot aect the tool-carrier except through the hammer.

lWhen the tool is held by the operator in Working position, the tendency is to force the tool-carrier in the direction of the arrow, Fig. 1, against the shoulder of the casing, so that the tool-carrier will always be in position to be struck by the hammer; but when the op erator sets the tool down after working, the stroke 0f the hammer will be greater, as the hammer and tool-carrier will move forward their full distance. The increased movement of the hammer will throw the ports out of line with the valve, thus stopping the tool.

As soon as the tool is pressed to the work again, the hammer will be moved in the cas# ing to such a position that its ports will be 'in 'line with the ports of the valve, and the hammer will be again set in motion.

Adapted to the hammer B and to the cap A of the casing is a valve D, having a portion dadapted to a seat as on the cap A and pressed against its seat by constant pressure at the rear, the main body of the valve extend ing into the central opening in the hammer. When the portion d of the valve is oft' its seat, the space a; at; the4 rear of the hammer B is in communication with the duid-inlet passage e', and the fluid under pressure will force the hammer forward to strike the blow on the tool-carrier, and after the hammer reaches a certain point the central passage d of the valve will communicate through a port cl2 with a port b5 and channel b in the hammer, which communicate with the chamber c3 in front ofthe hammer, and in the meantime the exhaust-port i will be uncovered by the hammer B, so as to exhaustthe fluid under pressure from the chamber w, and consequently the valve D will seat itself on the seat a3 and prevent the admission of fluid into the space on. On the return movement of the hammer B the port b5 will move out of line with the port (Z2 of the valve D and cut oit the admission of fluid to the forward end of the cylinder, and the exhaust-port i of the space as will be uncovered, allowing the air under pressure to escape. Acertain lost motion in the first return stroke of the hammer B is taken up, after which the hammer will move the valve off its seat a3 and allow fluid under pressure to pass into the space :c under the hammer,`and the operation is repeated.

I preferably insert a washer e in the bottom of the valve-chamber, and I form a passage c in the hammer, which gives a communication IOO between the valve-chamber and the atmosphere through the channel a and exhaustport a2, although in some instances this is not absolutely necessary. Y

In the casing is an exhaust-passage a, which communicates with the space in in the front of the hammer and opens into the channel a', as clearly shown in Fig. 1, and this passage a is closed when the tool is in operation by the head c of the tool-carrier; but when the tool is ont of operation the carrier, being thrown to its full outward limit, uncovers the passage a4, so that the said passage will communicate with the atmosphere and prevent the accidental starting of the tool due to the accumulation of liuid under pressure in the space no', which would leak through de fectivc joints or packing.

In some instances when large tools are cons trnctedl may reduce the tremble by arranging an annular piston F Within the casing, and so communicate the spaces y 'y' in the casing at each end of the piston with the iiuid under pressure that when the hammer strikes a blcvtr the piston F will move in the reverse direction, counteractin g the trembling effect of the blow to a certain extent, and as the hammer returns fluid under pressure may move thev piston in the opposite direction, which will also tend to reduce the tremble caused by the return stroke.

As shown in Fig. l, the space y communicates with the passage h through the port if, and the space y communicates with the space :r at the back of the hammer through the passage Z13 and port if* in the hammer. This piston I preferably make of leather or rawhide, and is preferably shaped as shown in the drawings; but it may be made of metal and of any shape Without departing from my invention.

In Figs. 4 and 5 I have shown the toolinits simplest form, dispensing with the annular piston.

I claim as my inventionl. The combination ot' the casing, a tool carrier, hammer within the casing adapted to strike the tool carrier, a valve adapted to a seat in the casing and having a port, a port in the hammer communicating with the forward end ofthe casing, with exhaust ports in each end of the casing, the whole so constructed, that as the hammer moves forward, the valve will be ofi its seat so as to admit uid under pressure to the rear of the hammer and When the hammer is moved to a certain position the ports of the valve will be uncovered forming communication with the forward end of the casing, the valve in the meantime being seated, substantially as described.

2. The combination in a pneumatic tool, of the casing, the hammer therein,'a channel a in the casing, a tool carrier adapted to said channel and a projection on the hammer resting at all times Within the channel and a valve for admitting 'fluid under pressure first to one end of the cylinder and then to the other, substantially as described.

3. The combination of the casing, the channel a therein open to the atmosphere at all times, a hammer adapted to reciprocate within the casing and having a projecting end extending into the passage a", a valve having a port, theham mer also havinga port, said valve being so constructed as to admit fluid under pressure to either end of the casing, the tool carrier being free to move forward to such an extent that when the tool is relieved of pressure the hammer will have an increased throw so as to throw its ports out ot' line with the valve automatically and stop the reciprocation of the hammer, substantially as den scribed.

et. The combination ot' the casing, the tool carrier, the plunger hammer adapted to reciprocate Within the casing and act upon the tool carrier, a fluid passage in the casing communicating with the space at each end of the hammer, with a valve adapted to a seat in the casing and arranged to cover or uncover a port in the hammer and to be acted upon by the hammer on its return stroke so as to move it otl its seat, with outlet ports communicating with the space at each end of the casing and to be covered and uncovered by the hammer in its reciprocation, substantially as described.

5. The combination of the casing, the hammer Within the casing, a tool carrier acted upon by the hammer, a valve adapted to the casing and tu the hammer, inlet and outlet ports, an annular piston adapted to reciprocate in the casing, spaces at each end of the piston communicating with the outlet and inlet ports, the ports being so arranged that the piston will travel in a direction opposite to that of the hammer, substantially as described.

6. The combination of the casing having a reduced portion, a tool carrier adapted to reciprocate in the said reduced portion, a cap attached to the casing and having an extension to which the fluid 7pressure pipe is connected, the iiuid passage ,c in said cap, a seat communicating with the space in the rear end of the casing, said cap having a valve seat a3, a plunger B adapted to reciprocate in the casing and having a projection b adapted to reciprocate in the channel a', and to strike the tool carrier on its forward movement, a port b5 and a passage b extending to the for- Ward end of the hammer, a valveD having a head adapted to the seat a3 and adapted to a valve Way inthe hammer B, a passage d and a port d2 in the valve, said port d2 aligning With the port b on the forward movement of the hammer and on the return movement of the hammer the valve Will be moved by the hammer off its seat, with exhaust ports i i one communicating with the one end of the casing and the other with the opposite end of the casing and so arranged that the ham- IDC rietis ont of use and moved to its extreme forward position, the said channel being open to the atmosphere at all times, substantially 15 as described.

In testimony whereof I have signed my name to this specication inthe presen ce of two subscribing Witnesses. f

JOHN G. CARLINET. Witnesses:

WILL A. BARR, Jos. H. KLEIN. 

